Electrolytic processes for the production of sodium hydroxide, hydrogen, and chlorine from brine are well known in the art.
U.S. Pat. No. 3,963,592, the entire disclosure of which is incorporated herein by reference, discloses an electrolytic process for the production of sodium hydroxide and chlorine from brine. Alternatively, the process produces sodium hydroxide and aqueous hydrogen chloride from brine and hydrogen. The process utilizes a gas anode which is capable of operating both as a hydrogen diffusion anode or a chlorine-producing anode. When operated as a hydrogen anode, the hydrogen is passed through a first layer and then a second layer of the anode and hydrogen ions formed react with chloride ions to produce hydrochloric acid in the anolyte. Accumulation of the hydrogen chloride, in the liquid anolyte, is undesirable when one desires a relatively pure and dry hydrogen chloride gas. It also reduces the current efficiency of the electrochemical cell if hydroxyl ions are to be generated at the cathode.